Rotary abrasive blast gun



Jan. 23, 1934. D c, COBLE Er' AL 1,944,404

ROTARY ABRASIVE BLAST GUN Filed Oct. 29. 1931 Paving (I Cale cgarles l?. Sianmeler MUSE( `ATTORNEYS Patented Jan. 23, 1934 ROTARY ABRASIVE BLAST GUN David C. Coble and Charles D. Steinmeier, Mishawaka, Ind., assignors to The American Foundry Equipment Company, Mishawaka,

Ind.,V a corporation of Delaware Application October 29, 1931. Serial No. 571,760

1 Claim.

The invention relates to apparatus for cleaning materials, and more particularly to a rotary gun for delivering a blast of sand or other abraslve.V Y

" 5. A principal feature of the present invention is the provision of an abrasive blast gun which rotates by the power obtained from the reaction of the blast. According to one form which the invention may take the gun may comprise a stationary conduit to which a mixture of precarburetted abrasive particles and carrying fluid is fed. The gun also may comprise a rotary conduit connected to and in line with said stationary conduit, said rotary conduit having a num- 15 ber of branch conduits supporting nozzles on the ends thereof. These nozzles are directed in such a way as to cause the gun to rotate about the main axis due to the reaction of the blast. The

. axes of the nozzles may be adjusted to regulate the speed of the gun and also to regulate the pattern or area cleaned by the gun.

The invention also consists in certain new and original features of construction and combi- 25. nations of parts hereinafter set forth andv claimed.

Although the novel features which are believed to be characteristic of this invention will be particularly pointed out in the claim appended hereto, the invention itself, as to its objects and advantages, and the manner in which it may be carried out, may be better understood by referring to the following description taken in connection with the accompanying drawing forming a part thereof, in which Fig. 1 is a vertical section through a gun according to the invention;

Fig. 2 is a detail showing how a nozzle is positioned with respect to the main axis;

Fig. 3 is a further detail illustrating how the angle of the nozzle may be changed; and

Figs. 4 and 5 illustrate adjustments of the nozzles for obtaining different patterns.

In the following description and in the claim, various details will be id'entied by specic names for convenience, but they are intended to be as generic in their application as the art will permit.

Like reference characters denote like parts in A, the several figures of the drawing.

In the drawing accompanying and forming part of this specification, certain specific disclosure of the invention is made for purposes of explanation, but it will be understood that the details may be modified in Various respects without departure from the broad aspect of vention.

Referring now to the drawing, the sandblast gun comprises a stationary part 9 and a rotary part 13. The stationary part 9 comprises a sta- 60 tionary bracket or support 10 having a .pair of bearings 11 and l2. The stationary support 10 also has a collar 16 which clamps a stationary pipe to which a fitting 1'7 is connected. A supply pipe 18 is connected to the fitting 17 and is 65 adapted to be supplied by a source of abrasive and carrying fluid which has already been carburetted or mixed, as, for example, a4 mixture of sand particles and air, the air carrying the sand particles in suspension.

The rotary element 13 of the gun comprises a sleeve 14 journalled in the bearings 11 and 12 for radial support and engaging the bearing 11 through a ball bearing 2S for axial support. A stuiiing box 19 is connected to the sleeve 14 including packing 29 and a gland 30 for sealing at the point at which the stationary pipe 15 .passes into the sleeve 14.

Connected at the lower end of the sleeve 14 is a fitting 20 to which are connected a plurality of branch conduits 21. Elbows are connected to the ends of branch conduits 21 and nozzle members 23 are connected to the elbows 22, as shown.

In operation, the gun rotates about the main axis, indicated by 40, due to the reaction of the blast issuing from the nozzles 23. It will be noted that so long as these nozzles are directed in a direction which is neither parallel nor perpendicular to the main axis there will be a cornponent tending to rotate the rotary element 13 about the main axis 40.

To adjust the speed of rotation, it is necessary to change the angle, indicated by X in Fig. 2, namely, the angle between the nozzle 23 and the main axis 40. This could be done by changing the nozzles 23 themselves to nozzles which have a diierent angle, or the entire elbow 22 and nozzle 23 may be rotated about the screw threads 24.

To adjust the gun for the desired pattern on the work the nozzle 23 would be adjusted through lQO the angle Y in Fig. 1. This .adjustment can conveniently be made by rotating the nozzle 23 about the screw threads 25. Fig. 4 illustrates a pattern with the nozzles directed toward the main axis 40 while Fig. 5 illustrates a pattern with the noz- 10j5 zles 23 directed away from the main axis 4G.

It will be understood that there are many advantages in the present construction. It will be noted that the corners or bends in the gun, such as at the fittings 17 and 20, are abrupt right 1110 the inangles. This serves to prevent any tendency for the sand and air to separate at these points. This construction also provides recesses or dead pockets which may fill up with sand to a certain extent and protect the fittings at the points opposite vthe entrance of the sand stream, these points being adjacent to plugs 42 and 41. p

The elbows 22 may be made of some special material which is especially able to withstand the scouring action of the sand blast, or, if desired, right angle elbows may also be placed at these points.

A further and important advantage of the in vertical, and either above or under the work Without interfering With the action or operation of the gun. The work should preferably be flat or located on a nat surface and the main axis 40 of the gun should be arranged approximately perpendicular to the surface, as illustrated, to obtain best results.

Furthermore, any number of nozzles may be used on the gun and any type of nozzle may be used.

While certain novel features of the invention have been disclosed and are pointed out in the annexed claim, it will be understood that various omissions, substitutions and changes may be made by those skilled in the art without departing from the spirit of the invention.

What is claimed is:

In a self-rotating, abrasive blast gun, a stationary conduit adapted to receive a precarburetted mixture of abrasive and carrying iiuid, a rotary element comprising a rotary conduit in line with said stationary conduit and connected thereto, a plurality of branch conduits connected to said rotary conduit, a nozzle on each branch conduit directed at an angle other than parallel or perpendicular to said rotary conduit whereby the reaction of the blast rotates said rotating element, and means for adjusting said nozzles about said branch conduits to change the speed of rotation, and means for adjusting said nozzles about the line of motion of said nozzles to change the pattern of the blast.

DAVID C. COBLE. CHAS. D. STEINMEIER. 

